Method and apparatus for sizing yarns



April 5, 1969 K. R. LOFGREN 3,438,102

METHOD AND APPARATUS FOR SIZING YARNS Filed. Sept. 25, 1967 Sheet of 4 Z8 INVENTOR.

KARL. R. LOFGRE-N lllllllli AL. ATTORNEY$ April 15, 1969 K. R. LOFGREN 3,438,102

METHOD AND APPARATUS FOR SIZING YARNS Filed Sept. 25, 1967 Sheet 2 of 4 April 15, 1969 K. R. LOFGREN 3,438,102

METHOD AND APPARATUS FOR SIZING YARNS Filed Sept. 25, 1967 Sheet 3 of 4 IM VENTOR KARL T2. LOFGEE-N ATTORNEYS April 15, 1969 K. R. LOFGREN 3,

METHOD AND APPARATUS FOR SIZING YARNS Filed Sept. 25, 1967 Sheet 4 of 4 EVE I MoT'o $2. 87

LASHER BRWECQNTEOL HEAT CONTROL CONTROL i i I 1 I I i. g i L4 43 l l 40 l F i/5 i. l g a l I I L J L 50 55 t 56" L 6O? 57' Powesz a SOURCE r t INVENTORI KARL. E. LOFCaRE-N M MZ A'ITOP NFYS United States Patent METHOD AND APPARATUS FOR SIZING YARNS Karl R. Lofgren, Gastonia, N.C., assignor to Cocker Machine and Foundry Company, Lowell, N.C., a corporation of North Carolina Filed Sept. 25, 1967, Ser. No. 670,211 Int. Cl. D03j 1/02; D02g 3/00 US. Cl. 2828 18 Claims ABSTRACT OF THE DISCLOSURE Method and apparatus for slashing, or sizing, textile yarns wherein a longitudinally moving sheet of warp yarns is impregnated with size, is then split into a plurality of yarn sheets, the size on the yarns is partially dried while the yarns are in split sheet condition to prevent adherence of the yarns to each other during and after final drying, and the sheets thereafter are combined and finally dried, and wherein the amount of heat applied to the yarns during partial drying is regulated in response to changes in the rate of longitudinal movement of the yarns to prevent overheating of and possible damage to the yarns.

This invention relates to a method and apparatus for slashing, or sizing, textile yarns.

In a conventional slashing operation, it is the practice to pass a longitudinally moving sheet of warp yarns through a sizing bath to impregnate the yarn sheet with size and to thereafter dry the size on the yarns, generally by the use of a plurality of drying cans. It is often a problem in such operations, particularly when high density sheets of warp yarns are being sized, that adjacent yarns in the sheets are in intimate contact during drying and are stuck together by the dried size, causing the yarns to be difiicult to separate in subsequent textile operations and resulting in loss or damage to the protective size coating thereon. This problem is particularly acute when sheets of natural fiber spun yarns, having a roughened or fuzzy surface, or of low-twist, multifilaments synthetic yarns are sized.

In an attempt to overcome this problem, it has been proposed to split the high density warp yarn sheet passing from the sizing bath into a plurality of less dense yarn sheets and to partially dry the size on the yarns in the plurality of yarn sheets prior to recombining the sheets for final drying. While reducing the tendency of the yarns to become stuck together, this partial drying proposal has created additional problems in that high intensity heat is utilized for the partial drying of the size which frequently results in overheating of the warp yarns particularly during those periods of slasher operation wherein the rate of longitudinal movement of the yarns is substantially decreased or when such movement is stopped. This overheating of the warp yarns during the partial drying of the size is highly undesirable since the yarns or the size coating thereon is usually damaged, and this problem is particularly acute with synthetic warp yarns.

Accordingly, it is an object of the present invention to provide a method and apparatus for slashing or sizing longitudinally moving sheets of warp yarns and for partially drying split sheets of the yarns prior to final drying which overcome the aforementioned problems and disadvantages heretofore encountered.

It is a more specific object of this invention to provide a method and apparatus of the character described where in heat is applied to the moving warp yarns in split sheet form to partially dry the size thereon and wherein the amount of heat applied to the warp yarns is regulated in response to changes in the rate of movement of the warp yarns to prevent damage to the yarns due to overheating.

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It is a further more specific object of the present invention to provide a method and apparatus as described, wherein heat is applied to opposite sides of the moving yarn sheets, and the amount of heat applied is regulated by moving the sources of the heat toward and away from each other and the yarn sheets therebetween in response to changes in the rate of movement of the warp yarns.

It is another object of the present invention to provide a method and apparatus for sizing yarns wherein a sheet of warp yarns is moved longitudinally, is impregnated with liquid size and is split into a plurality of moving sheets of warp yarns, and wherein the size on the warp yarns in the plural sheets is partially dried by heat applied to the warp yarns, the amount of heat being regulated in response to changes in the rate of longitudinal movement of the yarns, and wherein recirculating air currents are directed across the path of longitudinal movement of the yarns during partial drying of the size on the warp yarns to assist therein.

It is a further object to provide a slasher of the type described wherein the sheet splitting mechanism of the slasher may be readily adjusted to vary the spacing between split yarn sheets to facilitate thread up and operation of the slasher.

Some of the objects and advantages of the invention having vbeen stated, others will appear as the description proceeds, when taken in connection with the accompanying drawings, in which FIGURE 1 is a side elevation of a portion of the textile slasher of the present invention and showing the improved predryer device positioned between the discharge end of the size box and the receiving end of the final can drying section of the slasher;

FIGURE 2 is a front elevational view of the predryer device looking in the direction of the arrow 2 in FIGURE 1, with a sheet splitting mechanism attached to the support frame of the predryer omitted for convenience;

FIGURE 3 is an enlarged sectional view of the banks of heating elements of the predryer device, taken generally along the line 3-3 of FIGURE 2;

FIGURE 4 is an enlarged sectional view of the drying device taken generally along line 4-4 of FIGURE 1 and showing the bottom bank of heating elements;

FIGURE 5 is a dia'grarnmatical perspective view of the movable banks of heating elements of the predryer device, and additionally showing diagrammatically the control means for moving the banks toward and away from each other in response to changes in the rate of longitudinal movement of the warp yarns, and the associated control means for varying the heat in the predryer in the direction of longitudinal movement of the warp yarns therethrough; and

FIGURE 6 is a schematic wiring diagram of the control means for varying the heat in the predrryer.

Referring more specifically to the drawings, FIGURE 1 shows a portion of a slasher 10 embodying the features of the present invention and including a size box 12, a yarn sheet splitting mechanism 14 located adjacent the discharge end of the size box, and a predryer or partial drying device 16 positioned between the splitting mechanism and the receiving end of a can drying section 18.

As can be seen, a sheet of warp yarns 20 is longitudinally moved through the slasher by suitable slasher drive means, not shown. The sheet of warp yarns 20 passes through the size box 12 where it is impregnated with liquid size and is then delivered by squeeze rolls 21, 22 at the discharge end of the size box, through the sheet splitting device 14 and predryer 16 where the wet size-impregnated yarns are partially dried in split sheet condition (FIGURE 3). The plural sheets of yarn then pass to the first drying can 23 of the final drying section 18 where they are recombined and thereafter finally dried. Conventional slasher drive control means, indicated diagrammatically in FIGURE 5 at 26, are provided for controlling the rate of movement of the warp yarns through the slasher 10. Usually, this slasher drive control means has three positions (not shown), the first position being a stop position wherein there is no longitudinal movement of the warp yarns, the second position being a creep position wherein the warp yarns are moved longitudinally at a relatively slow or creep rate of speed, and the third position being the normal operating position wherein the warp yarns are moved at a relatively fast rate.

The predryer device 16 of the slasher of the present invention generally includes a support frame 28, a heating unit (shown in broken lines) 30, an air circulating system 32, and control means, generally indicated by the numerals 34 (FIGURE 1), 36 and 38 (FIGURE 5), for regulating the amount of heat applied to the plurality of yarn sheets passing through the heating unit 30 in response to changes in the rate of longitudinal movement of the warp yarns to prevent overheating thereof.

The heating unit 30 of the predryer device 16 may be best described by reference to FIGURES 3 and 4 and includes opposing heat sources positioned in straddling relation to the path of travel P of the plural yarn sheets and consisting of opposed banks 40, 42 of heating elements defining a heating zone and yarn sheet passageway therebetween. As seen, the banks of heating elements are of substantially identical construction and are disposed substantially parallel to the outermost yarn sheets of said plurality of yarn sheets. In most instances, the opposed banks will converge in the direction of longitudinal movement of the warp yarns, but may be considered as being generally horizontally supported on the support [frame 28.

The banks 40, 42 are composed of a plurality of heating elements, respectively shown as electrically energized infrared emitting elements 43, 43' which are mounted on respective elongate bracket members 44, 44' and extend substantially the full width of the banks (FIGURE 4). A plurality of reflecting elements 46, 46' are disposed between the respective heating elements 43, 43 in each of the banks and the reflecting elements in each bank are disposed in heat-reflecting relationship with the heating elements in the opposing bank for more effective utilization of the heat emitted by the heating elements in the partial drying of the size on the warp yarns during their passage through the heating zone. The backs of the banks 40, 42 of heating elements are enclosed by housings 47, 47' respectively, which are provided with a layer of suitable insulating material 48, 48', such as asbestos, to minimize heat losses from the banks during operation of the predryer device.

The infrared heating elements 43, 43 in each of the banks 40, 42 are arranged in a plurality of heating sections 5153 and 51-53, respectively, positioned along the direction of longitudinal movement P of the warp yarns. Suitable means, such as variable control units 55, 56 (FIGURES 5 and 6) are provided and electrically connected to the respective banks 40, 42. As shown in FIGURE 5 and in the wiring diagram of FIGURE 6, each of the control units are provided with three cycling controls 57-59, 57'59, respectively, which are each connected in series with the heating elements of a heating section and are connected in parallel with each other and to a power source 60 to supply electrical energy for variable time intervals during each cycle to the individual heating elements in each heating section of the respective banks 40, 42 of heating elements for varying the amount of heat emitted from each of the sections to control the amount of heat applied to the warp yarns passing through the passageway in the direction of longitudinal movement thereof to prevent overheating of the warp yarns.

Although the opposing heat sources of the predryer device are shown as plural banks of electrically energized heating elements emitting heat in the infrared range, other heat emitting elements may be substituted therefor, if desired. F or example, all the heat-emitting elements may be located in one bank on one side of the yarn sheets, while heat reflectors may be employed as the opposite bank, it being preferable to maintain some source of reflected or emitted heat on opposite sides of the yarn sheets to provide optimum partial drying of the size on the yarns during their passage through the heating unit of the predryer device.

The air circulating system 32 of the predryer device includes conduit means composed of a plurality of fixed conduit sections 62-65 (FIGURE 2) and movable conduit sections or opopsed end portions 66-69 which are positioned in straddling relationship to the path of travel P of the yarn sheets and serve to circulate air currents in a substantially closed path of travel into heat exchange relationship With the banks of heating elements of the predryer device and through the moving yarn sheets to facilitate partial drying of the size on the warp yarns.

The movable conduit sections 68, 69 are respectively attached to the back of the housings 47, 47' of the banks of heating elements. A plurality of nozzles 71, 71' are mounted in spaced intervals in the respective banks 40, 42 and along the direction of longitudinal movement of the yarn sheets. The nozzles have elongate slit-shape openings which preferably extend the full width of the banks (FIGURE 4) and serve to direct a plurality of longitudinally spaced streams of air (note arrows A in FIGURE 3) across the path of movement of the yarn sheets. A manually operated damper valve 72 is positioned in each of the nozzles 71 in the lower heating bank 40 and the valves 72 are positionable to vary the relative intensity of the streams to regulate the temperautre and humidity along the direction of longitudinal movement of the warp yarns.

The movable conduit sections 68, 69 attached to the heating banks are connected to the fixed conduit sections of the air circulating system by longitudinally extensible and retractable conduit sections 66, 67 which are of accordion pleat construction and permit their free movement in a vertical direction.

Located in the fixed conduit section 62 is an air impeller 75 (FIGURE 2) which is driven by a motor 76 mounted on the support frame 28. Rotation of the air impeller directs air currents through the conduit sections and across the yarn path of travel in the direction indicated by the arrows in FIGURES 2 and 3 to remove moisture from the passageway between the heating banks and assist in partially drying the size on the yarns. To further control the temperature and humidity of the air passing across the path of travel of the yarns, the upper end of the conduit section 62 is open, and a damper valve 78 is positioned in the conduit section. Its position is controlled by a handle :79 to permit a portion of the recirculating air to escape from the air circulating system and thereby control the moisture content of the air being circulated to facilitate the partial drying of the size on the warp yarns.

The control means for moving the banks of heating elements vertically toward and away from each other and the yarn sheets in the passageway for regulating the amount of heat applied to the yarn may be best described by reference to FIGURES 1 and 5. As diagrammatically shown in FIGURE 5, elongate flexible members, such as sprocket chains 80-83, are located adjacent the corners of the heating banks 40, 42, and each member has its terminal ends suitably secured to the corresponding corner portions of the opposing banks of heating elements. Each of the members is frictionally engaged and supported intermediate its ends by a rotatable element, shown as sprocket wheels 84-87, which is located vertically above the corresponding corner portions of the banks to which the ends of the flexible memher is attached. Pairs 84, 87 and 85, 86 of the sprocket wheels are mounted on respective elongate shafts 88, 89 which are rotatably secured to front and back vertical posts of the support frame 28. Suitably fixed on the outer front ends of the shafts 88, 89 are respective drive sprockets 90, 91 which are interconnected by an endless sprocket chain 92 to a smaller sprocket wheel 93 of a reversible drive motor 94 mounted on top of the support frame 28. As seen in FIGURE 5, the support shafts, sprocket wheels and flexible members serve to support the banks of heating elements in suspended position below the top of the support frame 28 so that rotation of the sprocket wheels by the reversible motor causes simultaneously shortening and lengthening of the respective reaches of each elongate flexible element to vertically move the banks of heating elements. Thus, by controlling the direction of rotation of the reversible motor 94, the banks can be simultaneously moved toward or away from each other and the sheets of yarn in the passageway therebetween.

To facilitate in guiding and maintaining the alignment of the heating banks 40, 42 during their vertical movement, guide rollers 95 (FIGURES 4 and 5) are mounted on the front corner portions of the banks and engage corresponding vertically extending trackways 96, 97 (FIGURE 4) secured to the inner faces of upright posts 98, 99 of the support frame to ride upwardly and downwardly therein during movement of the banks.

The reversible motor 94 is electrically connected to and controlled by the slasher drive control means, indicated diagrammatically at 26 in FIGURE 5. The control means 26 is suitably programmed to operate the reversible motor in response to changes in the rate of movement of the warp yarns so that When the slasher drive control means is moved to either its first or second positions whereby the longitudinal movement of the warp yarns is stopped or is at a predetermined low or creep speed, motor 94 is energized to move the banks of heating elements 40, 42 away from each other and the yarn sheets therebetween to reduce the amount of heat applied thereto. In like manner, when the slasher drive control means is moved to its third position so that the warp yarns are moved at a relatively high, normal operating speed, the motor 94 is energized to move the banks 40, 42 toward each other for normal heating of the warp yarns.

The sheet splitting mechanism 14 (FIGURE 1) of the slasher (FIGURE 1) comprises a plurality of generally parallel leasing bars 101 which extend generally perpendicular to the direction of the longitudinal movement of the warp yarns and are supported in a common plane by bracket arms, one of which, 102, is shown, engaging the end portions of the bars 101. The bracket arms are suitably mounted for pivotal adjustment about a horizontal axis on extension bars, one of which, 103, is shown, secured to the front vertical posts of the support frame 28. By rotatably adjusting the bracket arms to vary the common plane of the leasing bars 101, the spacing between the plurality of yarn sheets passing through the leasing bars can be varied. This adjustable feature is of particular benefit in that it facilitates initial thread up of the leasing bars and slasher, and permits closer control of the spacing between the warp yarns during operation of the slasher and partial drying of the size on the yarns.

The operation of the slasher of the present invention may best be described by reference to FIGURES l and 5. As shown, the wet size-impregnated sheet of warp yarns longitudinally passes from the squeeze rolls of the size box into and through the sheet-splitting mechanism, where it is split into a plurality of yarn sheets to separate the individual warp yarns. The spacing between the plural sheets of yarn may be controlled by angular adjustment of the plane of the bars, as previously described.

In normal high-speed operation, the plural yarn sheets pass through the predryer in a longitudinal direction between the opposing banks of heating elements, which are maintained in relatively closely spaced relation (FIG- URE 5) to supply suflicient heat to the yarn sheets to partially dry the size on the warp yarns while they are in separated condition. The emission of heat from the individual heating sections of the banks positioned along the direction of longitudinal movement of the sheets may be adjusted by the rheostats to provide optimum conditions for partial drying of the size on the yarns. In addition, the flow of air from each of the nozzles in the lower heating bank may be adjusted by the valves located therein to control the intensity of the air currents along the length of the heating zone. In like manner, the damper valve at the top of the conduit may be adjusted to remove a desired portion of the moisture and heat laden air from the recirculating air and facilitate proper drying of the warp yarns passing through the predryer. The yarn sheets emerging from the discharge end of the predryer are directed to the drying cam of the final drying section of the slasher where they are combined into a single sheet and advanced through the drying section for collection on a suitable warp beam.

In the event that it becomes necessary to stop or slow down the longitudinal movement of the warp yarns through the slasher, as in the case of repairing a broken yarn strand in the warp sheet, the slasher drive control means automatically actuates the reversible drive motor of the predryer to move the heating banks away from each other and away from the plurality of yarn sheets lying therebetween to prevent overheating of the Warp yarns without necessitating cutting off the power to the heating elements.

When the rate of movement of the warp yarns is returned to normal operational speed, the slasher drive control means actuates the reversible motor of the predryer to return the banks of heating elements to the normal predrying position adjacent the yarn sheets of the predryer.

That which is claimed is:

1. In a textile slasher having means for applying size to a longitudinally moving sheet of warp yarns, means for thereafter splitting the moving wet, size-impregnated sheet into a plurality of moving yarn sheets, means for partially drying the size on the plurality of yarn sheets while in split condition, and means for thereafter recombining the yarn sheets and finally drying the size on the combined sheets of warped yarns, the improvement wherein said means for partially drying the size on the plurality of yarn sheets comprises:

opposing heat sources positioned in straddling relation to the path of travel of the plurality of moving yarn sheets for applying heat to the warp yarns to partially dry the size thereon and mounted for movement toward and away from each other, and control means responsive to changes in the rate of longitudinal movement of the warp yarns through the slasher and connected to said opposing heat sources for moving said opposing heat sources toward and away from each other and the plurality of yarn sheets therebetween for regulating the amount of heat applied to the plurality sheets by said opposing heat sources to prevent overheating thereof.

2. Apparatus as defined in claim 1 wherein said opposing heat sources comprise a pair of generally opposed banks of heating elements mounted in spaced relation and defining a passageway therebetween for movement therethrough of the plurality of yarn sheets.

3. Apparatus as defined in claim 2 wherein said opposing heating sources include reflector means disposed between the heating elements in each bank and disposed in heat reflective relationship with the heating elements in the opposing bank for more effective utilization of heat from the heating elements in the partial drying of the size on the warp yarns.

4. Apparatus as defined in claim 2 wherein said heating elements in each of said banks are arranged in a plurality of heating sections along the direction of longitudinal movement of the warp yarns, and means connected to said sections of heating elements for varying the amount of heat emitted from each of said sections to control the amount of heat applied to the warp yarns passing through said passageway in the direction of longitudinal movement thereof to prevent overheating of the warp yarns.

5. Apparatus as defined in claim 4 wherein said heating elements comprise electrically energized heating elements emitting heat in the infrared range, and wherein said heat varying means includes variable means electrically connected to said heating elements.

6. Apparatus as defined in claim 1 including ai circulating means associated with said opposing heat sources and positioned in straddling relationship to the path of travel of the plurality of yarn sheets for circulating air currents in a substantially closed path of travel into heat exchange relationship with said opposing heat sources and through the moving yarn sheets to facilitate partial drying of the size on the warp yarns.

7. Apparatus as defined in claim 6 including means associated with said air circulating means for controlling the moisture content of the air being circulated to facilitate the partial drying of the size on the warp yarns.

8. Apparatus as defined in claim 6 wherein said air circulating means includes conduit means having opposed ends positioned on opposite sides of the path of travel of the moving yarn sheets, impeller means positioned in said conduit means for circulating air therethrough and across said path of travel, and means associated with said conduit means for removing a portion of circulating air and moisture carried thereby to control the temperature and humidity of the air passing across the path of travel of the yarns.

9. Apparatus as defined in claim 8 wherein said opposed heat sources includes a pair of opposed banks of heating elements positioned in straddling relation to the path of travel of the moving yarn sheets, and wherein said opposed ends of said conduit means are connected to said banks of heating elements and include means for directing a plurality of longitudinally spaced streams of air across said path of movement of the yarn sheets and for varying the relative intensity of said streams to regulate the temperature and humidity along the direction of longitudinal movement of the warp yarns.

10. Apparatus as defined in claim 9 wherein said means for directing a plurality of spaced streams of air comprises a plurality of nozzles positioned in said banks of heating elements and extending for substantially the full width thereof, said nozzles being spaced apart in the direction of longitudinal movement of the yarn sheets, and means positioned in each of the nozzles in one of said opposed banks for controlling air flow therethrough.

11. Apparatus as defined in claim 8 wherein said banks of heating elements are mounted for movement toward and away from each other, said conduit means includes extensible and retractable portions connected to said opposed ends thereof, and wherein said heat control means includes means for moving said banks of heating elements and said opposed ends of said conduits toward and away from each other and the yarn sheets therebetween.

12. Apparatus as defined in claim 11 wherein said opposing heat sources includes a support frame, said opposed banks of heating elements are generally rectangular in shape and are generally horizontally disposed on said support frame for vertical movement, and wherein said means for moving said opposing banks includes a plurality of elongate flexible members, each of said members having its terminal ends connected to corresponding corner portions of said opposed rectangular banks of said heating elements, a rotatable element mounted on said support frame above each of said corresponding corner portions of said banks and frictionally engaging the corresponding flexible membe intermediate its ends to suspend said banks of heating elements therebelow, reversible drive means connected to said rotatable elements for rotating said elements in di rections to vertically move said banks of said heating elements toward and away from each other, and wherein said slasher further includes control means for controlling the rate of movement of the warp yarns through the slasher, said slasher control means being connected to said reversible drive means for actuating said drive means to rotate said rotatable elements and move said banks of heating elements in response to changes in the rate of movement of the warp yarns.

13. Apparatus as defined in claim 1 and including the further improvement wherein said means for splitting the moving Wet size-impregnated sheet into a plurality of moving yarn sheets includes a plurality of generally parallel, spaced apart lease rods disposed generally perpendicularly to and in the path of longitudinal movement of the moving sheet of warp yarns, said bars lying in a common plane and being adapted to engage selected portions of the moving sheet of warp yarns to divide the yarns therein into a plurality of moving yarn sheets, and means supporting said rods for rotationable adjustment about an axis common to said plane to permit angular positioning of said plane of the rods, whereby the effective spacing between the plurality of yarn sheets may be regulated.

14-. In an apparatus for drying web material having means for longitudinally moving the web in a predetermined path of travel, opposing banks of heating elements disposed in straddling relation to said path of travel and being supported for movement toward and away from each other and said path, control means responsive to changes in the rate of longitudinal movement of the web for moving the banks of heating elements toward and away from each other to vary the amount of heat applied to the web, and air circulating means associated with said banks of heating elements and positioned in straddling relationship to the path of travel of the web for circulating air currents in a substantially closed path of travel into heat exchange relationship with said banks of heating elements and across the path of the web to facilitate drying of the web.

v15. A textile slashing operation comprising the steps of:

(a) longitudinally moving a sheet of warp yarns in a generally predetermined path of travel while (b) impregnating the sheet of warp yarns with a liquid slze,

(c) splitting the size-impregnated sheet into a plurality of yarn sheets,

(d) partially drying the size on the warp yarns while in plural sheet condition by (1) passing the yarn sheets through a heating zone defined by opposed heat sources while applying heat thereto,

(2) sensing changes in the rate of longitudinal movement of the yarn sheets, and

(3) regulating the amount of heat applied to the yarns in the heating zone in response to such changes by moving the opposed heat sources toward and away from each other to prevent overheating of the yarns,

(e) recombining the plurality of sheets into a single sheet, and

(f) finally drying the size on the warp yarns.

16. A textile slashing operation as defined in claim 15 including the further step of varying the amount of heat applied to the yarns in said heating zone along the direction of longitudinal movement of the warp yarns there- 9 through to facilitate the partial drying of the Warp yarns without overheating thereof.

17. A slashing operation as defined in claim 15 and further including the steps of circulating air across the heating zone in a direction generally perpendicular to the direction of longitudinal movement of the Warp yarns therethrough to assist in partially drying the size on the Warp yarns by removal of moisture from the heating zone.

18. A slashing operation as defined in claim 17 wherein said air is circulated in a substantially closed path containing the heating zone and the Warp yarns therein to reduce the loss of heat from said heating zone, and in- References Cited UNITED STATES PATENTS 5/ 1954 Andrews 2828 9/1958 Adams 28-28 LOUIS K. RIMRODT, Primary Examiner.

US. Cl. X.R. 

